Question

使用Docker Compose并尝试将spring引导Web应用程序容器与mysql容器链接时，我收到“java.net.UnkownHostException：mysql：unknown error”。

docker-compose.yml 更新＃1

version: '2'

services:
  web:
    depends_on:
    - db
    image: thomptr/rest-services-ui:latest
    ports:
    - "9000:9000"
    links:
    - "db:database"
    restart: always
    environment:
      SPRING_PROFILES_ACTIVE: dev
      envTarget: dev

db:
    image: mysql:5.7
    ports:
    - "3307:3306"
    volumes:
    - "/home/trevor/softwareDev/mySql/dump:/docker-entrypoint-initdb.d"
    environment:
      MYSQL_ROOT_PASSWORD: legion03
      MYSQL_DATABASE: dev
      MYSQL_USER: dbuser
      MYSQL_PASSWORD: legion03

application-dev.properties 更新＃1

spring.profiles.active=dev
server.contextPath=/restservices
server.port: 9000

spring.datasource.initialize=false
spring.datasource.platform=mysql
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://database:3306/dev

spring.datasource.username=dbuser
spring.datasource.password=legion03;
hibernate.level.logging=debug

spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.naming_strategy=org.hibernate.cfg.ImprovedNamingStrategy
spring.jpa.database=mysql
spring.jpa.show-sql=true
spring.jpa.generate-ddl=true
spring.jpa.database-platform=org.hibernate.dialect.MySQLDialect

来自/ dockercompose_web_1容器的

日志

 2016-07-01 04:17:24.119 ERROR 1 --- [ost-startStop-1] o.a.tomcat.jdbc.pool.ConnectionPool      : Unable to create initial connections of pool.
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
Caused by: java.net.UnknownHostException: mysql: unknown error
    at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)

更新＃2 Nguyen Sy Thanh Son提出的方法是正确的。我的解决方案使用public wait-for-it.sh脚本。请在此处查看我的解决方案：https://github.com/thomptr/DockerDemo

Answer 1

web容器在mysql容器启动之前启动时会发生此错误。

要解决此问题，我认为您应该在entrypont.sh web图片中添加一个脚本，如下所示

host="db"
password="$MYSQL_ROOT_PASSWORD" #mysql root password

until mysql -h "$host" -uroot -p$password; do
  >&2 echo "MYSQL is unavailable - sleeping"
  sleep 1
done

>&2 echo "MYSQL is up - executing command"

# start your app here

上面的脚本将等到mysql启动后再运行应用程序

应用程序的Dockerfile应包含：

# run app
COPY entrypoint.sh /
RUN chmod +x /entrypoint.sh

ENTRYPOINT ["/entrypoint.sh"]

Answer 2

我认为这个错误是由于第一个容器不知道谁是db。从容器A到容器B的链接不会修改两个容器中的/ etc / hosts。

实现此目的的另一种方法是使用别名。你应该在这里找到你需要的所有信息

https://docs.docker.com/compose/compose-file/#aliases

并修改spring param：

spring.datasource.url=jdbc:mysql://<whatever alias you choose for db>:3306/dev

如果有效，请告诉我。

Docker撰写（v2）UnkownHostException

2 个答案: